JCPenney CEO Ron Johnson has quietly begun to hike prices across the company’s stores, The Post has learned.

It’s a humiliating about-face as the former Apple exec scrambles to restore the traditional sales events he ditched last year.

The increases are significant, as prices return broadly to previous levels before Johnson slashed them in his “fair and square” initiative. The push permanently lowered prices while eliminating sales events and coupons in February 2012, sources said.

A pair of Nike swimming trunks priced at $25, for example, has been raised to $45, according to data reviewed by The Post.

A bikini top under the retailer’s Arizona label was hiked to $24 from $15, while an Arizona men’s polo shirt is now $14, up from $9, the data show.

Most prices have been dug up from old lists for everything from lingerie to bed linens, sources said. At the company’s headquarters in Plano, Texas, a Penney exec supervising one major department “just pulled that spreadsheet and went off those prices,” according to one insider.

Indeed, a deadline for merchants this week has forced them to make similar short cuts as they submit price increases storewide. “It’s the quickest way to do it,” said the source.

The plan, insiders say, is to catch shoppers’ attention by promptly discounting the newly marked-up goods in sales events — Penney’s traditional strategy for decades. The entire women’s apparel department, for example, is expected to be on sale most of the time going forward, with regular discounts of 20 percent to 25 percent.

That’s despite Johnson’s rants against “fake prices” last year as he cast himself as a retail revolutionary looking to transform the business model for department stores.

Last month, Johnson announced Penney will reintroduce sales on a weekly basis. But he didn’t explain how Penney planned to protect its margins amid the discounting, given that day-to-day “fair and square” pricing had already left them razor thin.

A few days later, on Feb. 24, Johnson further confused Wall Street analysts as he said he was sticking to his original “vision” on pricing, even as Penney reported a $552 million fourth-quarter loss.

“We believe the first price is the right price and so we’re going to price our merchandise so that it sells every day,” Johnson said on a conference call. “We fully expect over half the business we do to be at our everyday price.”

Nevertheless, sources said managers that same day told employees that discounting — and price increases to match — were coming.

The hikes have already hit selected categories at stores, with stickers bearing the raised prices awkwardly stuck on top of the old prices to cover them. The bulk of the rollout is slated to begin next month.